1. Field of The Invention
The present invention relates generally to a suspension system for an automotive vehicle which executes a damping force characteristic control over one or more shock absorbers. The present invention, particularly, relates to a suspension system for an automotive vehicle which can control the shock absorbers so as to provide an optimum damping characteristic for each of the respective shock absorbers without the generation of or interference by, electromagnetic waves and without any reduction in the actuator's driving torque.
2. Description of The Background Art
A Japanese Patent Application First Publication (Tokkai) No. Showa 61-215106 exemplifies a previously proposed suspension system for an automotive vehicle which carries out the damping characteristic controls.
In this previously proposed vehicular suspension system, each actuator which is actuated in response to the drive signal to rotate a damping coefficient changing disc which is disposed on a piston rod of each shock absorber. A drive circuit which drives each of the shock absorber actuators and a control unit which supplies a control signal to each of the drive circuits, is disposed within a vehicle passenger compartment. A wire harness is used to connect the above described control components.
Since a wire harness is used to interconnect between each control component (control unit or so-called, controller), drive circuits, and actuators described above, the wiring in the vehicle passenger compartment becomes quite complex.
It is possible to omit one line of the wire harness which interconnects both the control unit and drive circuit if the control unit is integrated with the drive circuit. However, the dimension of the control unit is accordingly increased and space in which to dispose the control unit becomes difficult to find.
Furthermore, since the branched lines of the wire harness which connect the drive circuits to the respective actuators are relatively long, radio wave (electromagnetic wave) noises are radiated from the branched lines and the actuator's driving torque is correspondingly reduced due to voltage drop caused by the ohmic resistances of the branched lines of the wire harness.